The present exemplary embodiment relates to the detection arts. It finds particular application in conjunction with cargo containers which are used to ship products, foodstuffs, and other materials from one country to another, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
Cargo containers are widely used for shipping materials by land or by water from one country to another. Knowing the contents of such containers has become of increasing importance in detecting potential threats. It has thus become extremely important to monitor the contents of such containers for harmful materials, such as explosives, harmful biological and chemical materials, and radiation materials.
U.S. Pat. No. 7,176,793 discloses a detection device in the form of a strip for use in an enclosed container. The detection strip includes sensors of macro, meso or nanosize, all of which are referred to herein as nanosensors, for detecting materials that are harmful to human beings within an enclosed container and for transmitting a corresponding resonance frequency. One or more detection strips are initially placed within a container, depending on the size of the container. The detection devices are designed to send off specific resonant frequency signals which can be detected by voltage changes and/or current changes which are correlated to any harmful material detected within the container. A serial number computer chip is provided for specifically identifying the detection device and transmitting a corresponding resonance frequency, which allows the container to be identified. A power source is provided for operating the detection strip. A hand-held or stationary monitor is provided for monitoring the container for any signals given off from the detection strips within the container. The detection devices are designed to give off a predetermined amount of background signal. In consequence, if no such signals are received, the container is highly suspect as being tampered with, allowing such a container to be quickly removed and its contents examined.
For some applications, hazardous materials may be at relatively low concentrations, for example hazardous nuclear materials may be distributed in amongst other materials or chemical or biological warfare agents may be in small concentrations within the container. As a consequence, the detection device may give off an intermittent or no signal. One solution is to enlarge the size of the detection strip. However, very large detection strips may be unwieldy and difficult to attach to the container.
The exemplary embodiment provides a solution to this problem by incorporating the nanosensors in a device which is mounted to one or more interior walls of the container. The nanosensors are extremely small detectors, of micro, meso, or nano-size. The signals output by the nanosensors can be received by one or more detection devices which communicate the signals to an exterior monitor.